Container dividers having improved stacking strength



United States Patent George 0. Charrier Cincinnati, Ohio Dec. 22, 1970The Procter & Gamble Company Cincinnati, Ohio a corporation of Ohioinventor App]. No. Filed Patented Assignee CONTAINER DlVlDERS HAVINGIMPROVED STACKING STRENGTH 2 Claims, 3 Drawing Figs.

0.8. CI. 206/65, 229/15; 217/30 int. Cl. 865d 1136, 865d 5/48, B65d81/05, B65d 85/00 Field of Search 217/36, 31, 22; 220/22; 229/42;206/65; 229/ 15, 14, 29-15;

[56] References Cited UNITED STATES PATENTS 1,182,664 5/1916 Evers217/34 1,880,897 10/1932 Drewsen... 229/15 1,917,886 7/1933 Hogan 229/152,633,285 3/1953 Kells 229/15 1,373,577 4/1921 Vallens 229/15X FOREIGNPATENTS 502,126 3/1939 Great Britain 217/22 Primary Examiner-Raphaell-l. Schwartz Attorneys-John V. Gorman and Richard C. Witte ABSTRACT: Atechnique for improving the stacking strength 7 of divider-equippedcontainers without incurring any additional materials cost. Suchimprovement is realized by dimensioning the slot lengths of interlockingsheet dividers so that slots opening at the lower side of the dividersare substantially longer than those opening at the upper side.

PATENTED 0513221970 Fig. 1

Fig. 2

Fig. 3

ATTORNEY CONTAINER DIV IDERS HAVING IMIROVED STACKING STRENGTHBACKGROUND OF THE INVENTION In the art of packaging, verticalinterlocking dividers are conventionally employed. These slottedpartitions are assembled in anorthogonal system to form cellularcompartments in which plastic bottles, dr a multiplicity of likearticles, can be shipped. Suc'h arrangement provides two primaryadvantages. The individualized compartments prevent the packagedarticles from coming into contact with and damaging one another.Secondly, the vertical dividers provide a certain amount of stackingsupport to the containers.

To establish the interlocking feature,.the slots of the intersectingdividers are oppositely disposed. At each junction, the slot of oneopens upwardly while that of the other opens downwardly. Generally theseslots are of equal length (i.e.

about half the inside height of the container). Therefore the slotlength ratio (the ratio of the length of the downwardly opening slots tothe length of the upwardly opening slots) is 1:1. The total length ofthe aligned slots is equal to the height of the dividers.

It has been found that conventionally formed dividers usually fail toincrease the container stacking strength to the full extent to beexpected in view of the edgewise compressive strength of the dividers.This shortcoming is due to the fact that the sections of the dividersintermediate the upwardly opening slots frequently are held in adeflected condition following the loading of the objects into thecontainer compartmerits. At high speed production rates it is virtuallyimpossible to avoid conditions which are responsible for suchdeflection.

PresentIy if the stacking strength of even a portion of the packedcontainers is insufi'rcient, thepaclrag'ing components are redesigned.The walls of the container, the dividers, or the packaged objectsthemselves are changed to construct them of stronger, usually moreexpensive, materials. However, since the added cost does not reflect animprovement to the product packaged in the container, but only serves tohelp prevent damage thereto, it represents a cost'which, if possible,should be eliminated. Desirably, package cost should be minimized to anextend consistent with the provision of adequate protection. Suchprotection is of paramount import in connection with the packaging ofplastic bottles or similar like articles in which the wall thicknessesare reduced,insofar as is possible, to reduce the quantity of expensivematerial from which these are constructed. Any container failure duringshipping subjects such articles to the possibility of stress cracking orirreparable indenture, either of which is a serious quality defect.

Also, if a package has a stacking strength greater than that required,the substitution of less expensive materials should be attempted if thiscan be accomplished without jeopardy to the article. This cannot bedone, however, unless the stacking strength is consistently at least asgreat as that required for adequate protection of the articles.

OBJECTS OF THE INVENTION It is an object of the present invention toprovide additional flexibility in the design of package dividers wherebythe same materials may provide an improved and consistent stackingstrength.

It is yet another object of this invention to increase the case strengthand article protection offered by interlocked, slotted, package dividersby designed variation of the slotting ratios thereof.

SUMMARY OF THE INVENTION system to form cellular compartments withinwhich said articles are received. The slots in the intersectingpartitions are in alignment, with those of one partition openingdownwardly and telescoped over an unslotted portion of the other partition. The slot of the other partition opens upwardly and is telescopedover an unslotted portion of the first partition. These dividers have auniform height along substantially their full length which is sufficientto impart stacking strength to said container and the combined length ofthe aligned slots is substantially equal to the height of thepartitions. The lowermost portions of the articles to be separated bythe divider are configured so as to retain the lowermost portion of saidpartitions in place while the uppermost portions of the articles are ofreduced size. The improvement of this divider comprises slotting thepartitions in such a way so as to improve the stacking strength of thepacked containers by making the lengths of the downwardly opening slotson said partitions substantially greater than the lengths of the alignedupwardly opening slots.

BRIEF DESCRIPTION OF THE DRAWINGS While the specification concludes withclaims particularly pointing out and distinctly claiming the subjectmatter which is regarded as forming the present invention, it isbelieved that the invention will be'better understood from the followingdescription taken in connection with the accompanying drawing in which:

FIG. 1 is a vertical sectional view of a packed container showingassembled within the container the interlocking, vertical partitions andtheir respective slots;

FIG. 2 is an elevational view of an interlocking divider member havingelongated downwardly opening slots; and

FIG. 3 is an elevational view of an interlocking divider member havingshortened upwardly opening slots.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will be describedherein with relation to packaging plastic bottles or the like. It willbe evident, however, that the improved divider arrangement may be usedin a container for packaging of any of a number of similar articles, thelower portions of which are configured so as to restrain the lowermostportions of the vertical partitions from lateral.

movement.

Referring now to FIG. 1 of the drawings, there is shown in verticalcross section a packed container, generally indicated by referencenumeral 10, employing the present invention; The packed container 10comprises an outer container 12, dividers 14, extending parallel to onepair of sidewalls of the container, dividers 16 interlocked with andoriented perpendicularly to dividers 14 and extending parallel to theother pairs of sidewalls of the container, and plastic bottles 18received within the cells formed by dividers l4 and 16. In theillustrated embodiment the bottles 18 are packed nine to the container,three bottles 18 per row by three rows long and therefore two each ofdividers l4 and 16 are required. If larger quantities of bottles 18 areto be placed in each container 10 the number of dividers 14 and/or 16will be correspondingly increased.

The container 12 while illustrated as constructed of corrugatedcontainer board, can be made of any suitable material. The top andbottom closures comprise closure flaps 20 extending from the sidewallsof the container. The flaps 20 are folded inwardly in overlappingrelation and secured by gluing or the like in a conventional manner.Since the container 12 in the drawing is square in horizontal section,the distal edges of each of the pairs of oppositely disposed flaps 20abut and present inner surfaces 22 which are effectively continuous. Ifthe container 12 was rectangularly shaped, the distal edges of closureflaps 20 attached to the narrow pair of sidewalls would normally beseparated. In this event, it is desirable to use a filler pad betweensuch distal edges, or other means to result in substantially planarinner surfaces 22 in order to equally distribute stacking loads, as iswell known to those skilled in the art.

The dividers l4 and 16 shown in FIGS. 2 and 3 can also be constructed ofcorrugated container board or other suitable materials. Dividers 14 areeach provided with two downwardly opening slots 22 having a length L anda width which approximates the thickness of divider 16 so that divider16 can be received therein. Dividers 16 are each provided with twoupwardly opening slots 24 having a length L and a width whichapproximates the thickness of divider 14 so that divider 14 may betelescoped therein. The number of slots in each divider is equal to thenumber of other dividers with which that divider will be interlocked.The spacing between the slots is dependent on the desired cell size.

Dividers I4 and 16 each have a height H which is substantially equal tothe sum of the lengths, L and L, of slots 22 and 24 and to the insideheight of the container 12 intermediate the inside surfaces 22. Thelength of each of the dividers l4 and 16 approximates the length of theinner sidewalls of the container 12 which it parallels.

The dividers l4, 16 are assembled in an orthogonal fashion to formcellular compartments 26 for the bottles 18 by aligning slots 22 ofdividers 14 with corresponding slots 24 of dividers l6 and telescopingthe dividers so that each slot embraces the aligned unslotted portion ofthe other, as shown in FIG. 1. This is a conventional operation theprocedures for which are well known to those skilled in the art.

The length L of the downwardly opening slots 22 is substantially greaterthan the length L of the upwardly opening slots 24. In this connection,the slot length ratio of L to L should fall in the range from about 2:1to about 7:1, preferably about 3:1, for reasons which will be apparentfrom the description hereinafter contained.

When the above-described dividers are interlocked and placed in thecontainer 12, nine individual cellular compartments 26 are formed. Thesidewalls of each cellular compartment conform as closely as ispractical to the base portion of bottles 18 to be received therein. Thebottles 18 are thereby restrained from free movement in the horizontaldirection. For example, where the base of the bottle 18 comprises curvedsurfaces, the side surfaces of each cell 26 are preferably tangentthereto. By base portion" is meant the lowest third or so of the bottle18. Due to such construction and relationship, not only are the bottles18 prevented from shifting, but the bottles 18 retain the lowermostportions of dividers l4 and 16 in the exact position desired, i.e.,coplanar with the intermediate portions of the dividers.

As will be noted in FIG. 1, the dividers of the present invention areintended for use with articles, e.g. bottles 18, the upperrnost portionsof which are of reduced size. In the illustrated embodiment, the upperportion 28 of the bottle 18, whose height is approximately equal to orless than the height H of dividers I4, 16, is spaced inwardly from theside surfaces of the dividers defining each cell 26. This means that theupper portion 28 of bottles 18 cannot be employed in maintaining theuppermost portions of the dividers 14, 16 coplanar with the intermediateportion of the dividers.

Whereas the prior art discloses dividers whose uppennost portionsdeflect easily and as a,. consequence thereof the stacking supportprovidedthe container by said dividers is not as great as it should bein view of the materials used, the propensity of the uppennost portionof the dividers of the present invention to deflect is substantiallyreduced. The uppennost portions intervening the upwardly opening slotsof conventional dividers are readily moved and held in a deflectedcondition under the handling and packaging techniques in use inindustry. Moreover, this deflection is'increased upon application of anystacking load to the divider. In use, the total deflection directlyinfluences the amount of support provided the container by the dividers.The smaller the deflection, the greater the stacking strength providedby the divider. The greater the deflection, the smaller the stackingstrength provided the container by the divider. Thus,

it is primarily due to the propensity of such uppermost portions todeflect that conventional dividers fail at loads far below the loadsthey are potentially capable of supporting. The present inventionshortens the moment arm of such portions (which is equal to the length Lof the upwardly opening slots of dividers 16) so that its propensity todeflect is greatly reduced and the amount of support provided therebygreatly increased.

Actual tests prove the in-use efiicacy of this invention. Top to bottomcontainer compression tests were performed on a standard compressiontesting machine following the fixed procedure established by theAmerican Society for Testing Materials. The test was standardcompression test D 642 [American Society for Testing Materials: ASTMStandards on Paper and Paper Products and Shipping Container, p. 73(1962 with the exception that the container closure flaps were notsealed. The container (measuring 20 inches long, I 1- inches high, and 9inches wide) was packed with 12 bottles, 3 rows, 4 bottles per row (thenecks of the bottle were cut off so that the bottles could notcontribute to the compressive strength). The bottles were separated byconventional dividers made from the same material as the container, "C"flute cardboard. However, the slot length ratio was varied from test totest, covering a range extending from the conventional 1:1 up to amaximum of 7: l The results of the test on dividers having theconventional slot length ratio of 1:] were used as standard or thecontrol. Table 1 below reveals the improvement in stacking strengthachieved by such variation of the slot length ratio;

TABLE 1 Stacking strength Slot Length Ratio (1/1): (percentimprovemerttg 1 Standard (conventional).

The slot length ratio of the present invention ranges from about 2:1 toabout 7:1 and for greatest benefit preferably is about 3:]. When theslot length ratio is below about 2:1, i.e., about a conventional slotlength ratio of 1:1 or less the previously described problem ofdeflection is experienced.

However, as the slot length ratio gets larger than conventional, e.g.,about 2:1 or greater, the propensity to deflect decreases and an averageimprovement in stacking strength is experienced using identicalmaterials.

It is noted that as the slot length ratio gets larger than 3:1, thecorresponding improvement in stacking strength (over conventionallyslotted dividers) attendant to successive increases in slot length ratioabove the conventional 1:1 is not as great. This pattern of reducedstacking strength improvement, as the slot length ratio gets larger thanabout 3:1 is thought to be due to the susceptibility of the divider 14to tearing and handling damage. The damage results in weakening of thecompressive strength of that portion of dividers l4 immediately aboveslots 22. As that portion gets smaller with slot length ratios greaterthan 3:1, the more severe the weakening under identical handlingconditions. When the slot length ratio exceeds 7:1, the compressivestrength of the portion is so weakened that the stacking strengthprovided thereby is no greater and sometimes even less than when theslot length ratio is the conventional l: l

If desired, the present invention can be employed to improve thestacking strength of containers housing a plurality of layers ofobjects, each layer of which is received in a cellular divider structureconforming to the above description, wherein the slot length ratios liein the aforesaid range of from about 2:1 to about 7:1, preferably 3:1.In this case'the layers are preferably separated by separator sheets ofcardboard or the like, the sum of the cumulative heights of the dividersand of the thicknesses of the separator sheets, if used, being equal tothe inside height of the container. Thus, the divider structure for eachlayer is adapted to impart stacking strength to the container and eachis provided with slot length ratios designed to achieve the benefits ofthe present invention.

Many modifications of the above invention may be used and it is notintended to limit the invention to the particular embodiment shown anddescribed. The terms used in describing the invention are used in theirdescriptive sense and not as terms of limitation,

Iclaim: I 1. A stackable, divider-equipped package comprising acontainer having a parallelepipedal configuration and at least one layerof objects, said layer comprising vertically extending generallyimperforate, planar dividers, said dividers being slotted andinterlocked in an orthogonal system to form a cellular structure, eachcell of said cellular structure having an object therein, said objectsbeing similarly shaped and similarly oriented within said container,said container having at least two spaced, planar support surfacesbetween which said layer is located, the planes of said support surfacesbeing substantially horizontal, said slots in intersecting dividersbeing in alignment with that of one divider opening downwardly andtelescoped over an unslotted portion of the other divider and the slotof said other divider opening up wardly and telescoped over an unslottedportion of said one divider, the length of each said divider beinggenerally equal to the inside length of the side of said containerdisposed in a vertical plane substantially parallel to the plane of saiddivider. said dividers each havinga uniform height along substantiallyits full length, said height of said dividers being substantially equalto the vertical distance betweensaid support surfaces within saidcontainer, said length of said aligned slots combining to approximatelyequal the height of said dividers, said objects having their lowermostportions sized and configured to retain the lowennost portions of saiddividers in substantially fixed orthogonal relationship substantiallycoplanar with the intermediate portions thereof, said objects havingtheir uppermost portions sized and configured to preclude said uppermostportions of said objects from similarly retaining the uppermost portionsof said dividers, each of said objects being supported by the lowermostof said horizontal spaced supports, said dividers havingslot-lengthratios in the range of from about 2:1 to about 7:1, whereby the stackingstrength of said package is improved.

2. The package of claim 1 in which theslot length ratio is about 3: l.

